Great Plains NTA2007HD Operator Manual - Manual (Page 98)

94 Great Plains Manufacturing, Inc. Contents Index NTA607/2007HD
166-283M Contents Index 04/04/2011
Marker Adjustments
Review “Marker Safety Information” on page 59 before
adjusting markers. There are four operating adjustments
for markers:
• Marker Extension: (page 95)
Once set for a specific row spacing, this only needs
periodic checking to ensure the clamp is secure.
• Marker Tension: (below)
You may want to adjust the spring tension to ensure
the markers track uneven ground, and do not drag
excessively when markers are folded.
• Disk Angle: (page 96)
(below) Even if your row spacing rarely changes, you
may need to adjust disk angle for soil conditions and
planting speed.
• Marker Speed: (page 96)
Once initially set by your dealer, this rarely needs
modification.
There are also two maintenance items for markers:
“Marker Hydraulic Bleeding” on page 130
“Marker Shear Bolt” on page 130
Marker Tension Adjustment
Refer to Figure 83
The strength of the mark is a function of marker arm
weight at the disk. A spring
behind the pivot assembly
acts against some of that weight. The spring is adjust-
able, and may be used to increase or decrease force at
the marker disk.
The suggested initial marking force is 23 kg (50 lbs.). For
marking forces up to this value, use the scale included
with the drill to lift the extended marker disk.
To adjust the marking force:
1. Fold the markers (page 58). This minimizes spring
tension for adjustment.
2. Set the marker hydraulic circuit to Neutral.
Shut off the tractor.
3. Loosen the eyebolt jam nut (on the top side of the
bracket).
4. Turn the adjust nut to change marking force:
Loosen this nut (relaxing the spring) to increase
marking force.
Tighten this nut (tensioning the spring) to decrease
marking force.
5. Tighten the jam nut to secure the new setting.
Impact / Crush / Pinch / Sharp Object Hazards:
Make all adjustments with tractor hydraulics shut down, and
the marker circuit in Float. Keep all persons clear of both
markers and their sweep arcs when testing adjustments. The
marker that moves may not be the one expected. A folding or
unfolding marker is a crushing hazard, and moving sharp
object hazard, that can cause serious injury or death. It has
multiple pinch points.
Null4:
Note: If the marker spring force is set too low, the marker
may fail to return to its cradle when folded.
Figure 83
Right Marker Tension Spring
31198
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2
3
1
2
3